TERROIR:

Major components of terroir are soil (as the word suggests) and local topography, together with their interactions with each other and with macroclimate. The holistic combination of all these is held to give each site its own unique terroir, which is reflected in its wines more or less consistently from year to year, to some degree regardless of variations in methods of viticulture and wine-making. Thus every small plot, and in generic terms every large area, and ultimately region, may have distinctive wine-style characteristics which cannot be precisely duplicated elsewhere. The extent to which terroir effects are unique is, however, debatable, and of course commercially important, which makes the subject controversial.

Dr. John Gladstones and Dr. Richard Smart, The Oxford Companion to Wine